Chempro

Evaluation of Electrostatic Precipitator Performance at Raw Mill Plant Unit 11 of PT Indocement Tunggal Prakarsa Tbk. Bogor, West Java

Farlina Hapsari — 2026-06-30

PT Indocement Tunggal Prakarsa is a cement manufacturing company whose production activities involve grinding and burning materials, resulting in environmental pollution in the form of dust into the air. These particulate emissions originate from the Raw Mill unit. The maximum standard limit applied to PT Indocement is 60 mg/m3. Efforts to minimize dust generated in this unit include installing dust control devices such as Electrostatic Precipitators (EP), preventing dust from being released directly into the atmosphere. Electrostatic Precipitators are devices that function as dust collectors. Their efficiency in capturing dust can reach 99.96%. In other words, almost all dust can be captured by Electrostatic Precipitators. The factor influencing the increase in dust emissions in these devices is the inlet temperature. The higher the temperature, the higher the resistivity of the dust, making it more difficult to capture.

Utilizing Coffee Ground Waste In Making Liquid Soap Scrub

Julia Putri Cantika¹ — 2026-06-30

The increase in national coffee consumption has an impact on the accumulation of coffee grounds waste (Spent Coffee Grounds) which is at risk of polluting the environment if not managed properly. This study examines the use of coffee grounds waste as a natural scrub ingredient in liquid soap formulations to provide safe exfoliation functions for the skin. The purpose of the study was to determine the optimal concentration of coffee grounds on the physical-chemical characteristics of liquid soap according to SNI 4085:2017 standards. The research method was carried out through laboratory experiments by varying the concentration of coffee grounds (0%, 3%, 6%, 9%, and 12% w/w) and Sodium Laureth Sulfate (SLS) as a surfactant (5%, 10%, 15%, 20%, and 25% w/w). Coffee grounds were processed through drying at 60°C and sieving with a size of 120 mesh before being added to the soap base. Test parameters included pH value, viscosity, foam stability, homogeneity, free fatty acids, free alkalis, as well as organoleptic and irritation tests on panelists. The results showed that the addition of coffee grounds significantly increased the soap viscosity to 12,890 cP at the highest concentration and increased foam stability by up to 95%. All formulations had a pH range of 4.3–5.7, which is compatible with the skin's acid mantle, making them safe to use. Panelist test data confirmed that coffee grounds concentrations of 9% and 12% with SLS levels above 15% produced liquid soap with excellent cleaning power, a comfortable scrub texture, and did not cause skin irritation. In conclusion, coffee grounds waste is effective for use as a scrubbing agent in liquid soap with physical characteristics that meet industrial quality standards and provide economic added value to organic waste.

Evaluation of Alum and Poly Aluminium Chloride (PAC) Coagulant Effectiveness on CaCO₃ Reduction through Sedimentation Process

Claudia Shinta Octa Wibowo — 2026-06-25

Sedimentation is a solid–liquid separation process whose effectiveness can be improved through coagulation and flocculation. This study aimed to evaluate the effect of coagulant type and dosage on the reduction of calcium carbonate (CaCO₃) concentration in water. The coagulants used were alum and Poly Aluminium Chloride (PAC) with dosage variations of 40 g and 60 g. CaCO₃ concentration before and after treatment was analyzed using EDTA complexometric titration, while process performance was evaluated based on removal efficiency. The results showed that all treatments reduced CaCO₃ concentration. Alum at 40 g and 60 g achieved removal efficiencies of 25.00% and 33.33%, respectively, while PAC at 40 g and 60 g achieved 33.33% and 43.75%, respectively. PAC at 60 g showed the best performance due to its ability to form more stable and settleable flocs.

Evaluation of Ion Exchange Performance in Reducing TDS and Water Hardness at Various Regenerant Concentrations

Claudia Shinta Octa Wibowo — 2026-06-25

Ion exchange is a water treatment method used to reduce dissolved ions and hardness-causing ions through ion exchange mechanisms on resin surfaces. This practice-based study aimed to evaluate the effect of regenerant concentration on the reduction of total dissolved solids (TDS) and water hardness using an ion exchange resin column. The experiment began with flow rate calibration based on valve opening variations. The main experiment was conducted at a valve opening of 50° with a flow rate of 25.00 mL/s for 90 minutes using regenerant concentrations of 2%, 4%, and 6%. The results showed that the 2% regenerant concentration provided the most stable performance, reducing TDS from 50.15 ppm to 29.80 ppm and hardness from 8.21 ppm to 3.20 ppm as CaCO₃. The final removal efficiencies were 40.58% and 60.98%, respectively. These findings indicate that increasing regenerant concentration does not always improve ion exchange effectiveness under the laboratory operating conditions.

Production Of Bioethanol From Fermented Cassava Rubber Using Cigading Yeast

Virli Febrian Al-Kausar — 2026-06-25

Rubber cassava (Manihot glaziovii) is a high-starch agricultural resource with considerable potential as a feedstock for bioethanol production; however, its utilization as a food source is limited due to the presence of toxic hydrogen cyanide (HCN). This study aimed to investigate the effect of fermentation time on bioethanol production from rubber cassava using a local yeast strain, Saccharomyces cerevisiae Cigading. The research was conducted through several stages, including raw material preparation, starch hydrolysis using 0.4 M sulfuric acid (H₂SO₄) to convert starch into fermentable sugars, fermentation with varying durations of 5, 10, and 15 days, and purification of the fermented broth by distillation. The parameters analyzed included glucose content after hydrolysis, fermentation and distillation yields, physical characteristics of the resulting bioethanol, bioethanol yield per kilogram of cassava, and flame test performance. The results showed that the glucose content after hydrolysis ranged from 22.92% to 23.31%, indicating that the hydrolysis process was effective and produced relatively uniform sugar concentrations. Variations in fermentation time significantly affected bioethanol production, where fermentation for 5 days produced 0.0217 L/kg of cassava with a small and unstable flame, fermentation for 10 days produced 0.094 L/kg with a fairly stable flame, and fermentation for 15 days resulted in the highest bioethanol yield of 0.1056 L/kg with a large and stable flame. Overall, the findings demonstrate that increasing fermentation time enhances both the quantity and quality of bioethanol produced from rubber cassava, and that the local Saccharomyces cerevisiae Cigading yeast exhibits good fermentation performance and adaptability when utilizing rubber cassava as a substrate.